The present invention relates to an automatic washing machine having a tub posture tilting mechanism and, more particularly to a full automatic washing machine having a tub posture tilting mechanism suitable for washing softly the delicate washing clothes such as the wool sweater and the lingerie.
The automatic washing machine according to the present invention has a tub posture tilting mechanism for tilting or inclining both of a posture of a washing tub and a posture of an outer tub. The standard washing clothes is washed in the washing tub using a washing liquid at a vertical state of the washing tub and the delicate washing clothes is washed softly in the washing tub using the washing liquid at an inclined state or a tilted posture of the washing tub according to the operation of the tub posture tilting mechanism structure.
In a conventional automatic washing machine, for example disclosed in Japanese Utility Model Laid-Open No. 205482/1986, a barrel-like shape washing tub is supported rotatively in a washing machine main body through a horizontal shaft and a barrel-like outer tub installed rotatively at an outer peripheral portion of the washing tub through another horizontal shaft in the washing machine main body.
The washing tub and the outer tub are rotated together in the washing machine main body through an operation according to a rack gear and pinion gear mechanism structure which is provided on and engaged with the outer peripheral portion of the outer tub. Namely, the washing tub and the outer tub are rotated together in accordance with the rotation of the rack gear and pinion gear mechanism structure.
A tub posture change-over apparatus for the postures of the washing tub and the outer tub or a motor for rotating the outer tub is provided in the washing machine main body. According to an operation of the tub posture change-over apparatus, the postures of the washing tub and the outer tub are changed over at two ways, namely at a vertical state in which another horizontal shaft is positioned at a vertical direction or at a horizontal state in which another horizontal shaft is positioned at a horizontal direction.
In the above stated conventional automatic washing machine, with the condition that both of the postures of the washing tub and the outer tub are maintained at the vertical state according to the operation of the tub posture change-over apparatus, the standard washing process is carried out using a pulsator which is mounted in the washing tub. The standard washing process for the standard washing clothes is carried out with the washing liquid swirling flow caused according to the high speed rotation of the pulsator.
Besides, with the condition that both of the postures of the washing tub and the outer tub are maintained at the horizontal state by the operation of the tub posture change-over apparatus, the washing tub is inclined at the horizontal direction and then the washing tub is rotated with a comparative slow speed. The delicate washing clothes is washed softly in the washing liquid similar to the washing process in a rotative drum type automatic washing machine. This soft washing process for the delicate washing clothes is carried out without the rotation of the pulsator.
Namely, by maintaining the postures of the washing tub and the outer tub at the horizontal state, the delicate washing clothes such as the wool sweater and the lingerie can be washed softly according to the low speed rotation of the inclined washing tub.
Further, by maintaining the postures of the washing tub and the outer tub at the horizontal state, the drying process is carried out according to the rotation of the washing tub.
As stated above, according to the conventional automatic washing machine, by maintaining the postures of the washing tub and the outer tub at the vertical state, the standard washing process suitable for washing the standard washing clothes is carried out by the washing liquid swirling flow using the pulsator.
Further by maintaining the postures of the washing tub and the outer tub at the horizontal state, the washing tub is rotated at the comparative low speed and the delicate washing clothes such as the wool sweater and the lingerie can be washed softly by rotating the washing tub at the comparative slow speed without a strong agitating force by the pulsator. Accordingly, there has a merit in which the delicate washing clothes dispenses with no injury.
However, when the barrel-like shape washing tub and the outer tub are received in the washing machine outer frame, many dead spaces are formed at the corner portions and so that it has a demerit with respect to the space aspect and further it is difficult to mold integrally such a barrel-like shape washing tub having a complicated shape.
Further, it is necessary to position always the turning fulcrum during the rotation for the horizontal state and the vertical state at a center point in the longitudinal cross-section having a substantially circular shape of the washing tub, regardless of the gravitational position of the washing tub.
Therefore, it is not allowed to set the turning fulcrum at the most suitable position which is a gravitational position under the consideration of the vibration-prevention during the spinning process which is a high speed rotation time by the washing tub.
Further, since the longitudinal cross-sectional shape of the washing tub is the substantially circular shape, the rotational axis of the washing tub inclines diversely, accordingly there is a little change in the behavior of the delicate washing clothes and there is little room to improve a cleaning efficiency in the delicate washing clothes.